Hello Stardog
Glad you are enjoying.. looks good eh
1. No not as far as I know.
2. You'd have to replace the splash.wav with another, with nothing in , or different sound.
...\WOFF\OBDWW1 Over Flanders Fields\campaigns\CampaignData\ShellMusic\Splash.wav
Maybe rename it for now as a backup, then copy button1.wav and rename it to Splash.wav
3. If it runs better use the game's one just make sure you are using one or the other, and not setting driver AA to "enhance.." which uses both at the same time.